Development of high resolution diffraction gratings for the EUV and soft X-ray energy ranges is an area of interest both in modern astronomy and in precision spectroscopy. Specifically, high resolution diffraction gratings can be used in a number of spectroscopic applications at synchrotron facilities around the world. A relatively new exciting development in high resolution soft X-ray spectroscopy is a method of Resonant Inelastic X-ray Scattering (RIXS) that potentially allows to directly measure the energies of soft excitations of correlated electronic systems such as high Tc superconductors. However, in order to realize the potential of this method, a dedicated spectrometer must achieve energy resolution of about 10 meV in the 100-eV to 5-keV photon energy range. This resolution corresponds to resolving powers that are up to 100 times greater than currently achieved resolution powers. One way to improve the resolution of RIXS spectrometer is to use the first order diffraction of a grating with an ultra-high density of grooves. Fabrication of suitable ultra-high density grating structures, however, presents a number of challenges that impede the development of such gratings. New fabrication methods that can be used to obtain gratings with ultra-high density of grooves are desirable.